3rd Generation Partnership Project (3GPP), a typical system of general mobile communication systems, has defined an Evolved Packet System (EPS) and introduced a Mobility Management Entity (MME) of a network, for next-generation communication.
This mobile communication system has presented a scheme for providing high-speed communication services in the next-generation mobile communication by improving the protocol used in 3GPP 3G Accordingly, the conventional mobile communication system has strengthened the security management scheme such as performing a security mode by introducing the Non Access Stratum (NAS) protocol concept secured in a NAS layer in addition to the authentication process and the security process that is performed in a wireless access layer.
However, the security may not be well ensured when the definition of the current NAS protocol and the definition of security of the related protocol are used to support services between a User Equipment (UE) and a server or between a UE and a UE in a machine-type communication environment.
In the mobile communication system, when a UE selects one operator, it stores security information for the operator and other information, and accesses the operator for communication. When the UE moves to another operator, it should use a Universal Subscriber Identity Module (USIM) or a Universal Integrated Circuit Card (UICC) belonging to the new operator.
Accordingly, a method is required that sets up an operator early, or more efficiently supports a change in operator by improving a process of making it possible to store security and subscriber-related information in a subscriber identity module in which a change in operator is not recorded or an early operator is not set up in a mobile communication system.